Fundamental Research Center, Shanghai Yangzhi Rehabilitation Hospital (Shanghai Sunshine Rehabilitation Center), Frontier Science Center for Stem Cell Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
The Center for Reproductive Medicine, Shanghai East Hospital, Tongji University, Shanghai, China.
Protein Sci. 2024 Aug;33(8):e5126. doi: 10.1002/pro.5126.
Histone phosphorylation is instrumental in regulating diverse cellular processes across eukaryotes. Unraveling the kinases that target specific histone sites is key to deciphering the underlying mechanisms. Among the various sites on histone tails that can undergo phosphorylation, the kinase responsible for H3.3S31 phosphorylation remained elusive. Since both H3.3S31ph and H3T3ph occur specifically during mitosis, and Haspin is the known kinase for H3T3 phosphorylation, we investigated its potential role in H3.3S31 phosphorylation. We employed CRISPR/Cas9, RNA interference, and specific small molecule inhibitors to eliminate Haspin function in various cell types. Our data consistently revealed a link between Haspin and H3.3S31ph. Furthermore, in vitro kinase assays provided evidence supporting Haspin's contribution to H3.3S31ph. Loss- and gain-of-function experiments targeting Haspin and Aurora B further suggested a hierarchical relationship. Haspin acts as a downstream kinase of Aurora B, specifically orchestrating H3.3S31 phosphorylation in mESCs. This study unveils a novel role for Haspin as a kinase in regulating H3.3S31 phosphorylation during mitosis. This discovery holds promise for expanding our understanding of the functional significance of Haspin and H3.3S31ph in mammals.
组蛋白磷酸化在调节真核生物的各种细胞过程中起着重要作用。揭示靶向特定组蛋白位点的激酶对于破译潜在机制至关重要。在组蛋白尾部可以发生磷酸化的各种位点中，负责 H3.3S31 磷酸化的激酶仍然难以捉摸。由于 H3.3S31ph 和 H3T3ph 都只在有丝分裂期间特异性出现，并且 Haspin 是已知的 H3T3 磷酸化激酶，我们研究了它在 H3.3S31 磷酸化中的潜在作用。我们使用 CRISPR/Cas9、RNA 干扰和特定的小分子抑制剂来消除各种细胞类型中 Haspin 的功能。我们的数据一致揭示了 Haspin 和 H3.3S31ph 之间的联系。此外，体外激酶测定提供了支持 Haspin 对 H3.3S31ph 贡献的证据。针对 Haspin 和 Aurora B 的失活和功能获得实验进一步表明了一种层次关系。Haspin 作为 Aurora B 的下游激酶发挥作用，专门在 mESCs 中协调 H3.3S31 磷酸化。这项研究揭示了 Haspin 作为激酶在有丝分裂过程中调节 H3.3S31 磷酸化的新作用。这一发现有望扩展我们对 Haspin 和 H3.3S31ph 在哺乳动物中功能意义的理解。
